I built and offline friendly app, was not offline first, but it was my first PWA, the idea was that a pilot could have our web page open at high altitudes, pote

I built and offline friendly app, was not offline first, but it was my first PWA, the idea was that a pilot could have our web page open at high altitudes, potentially with bad service, and they could still interact with anything, once back online, it would push any changes they made. I implemented it with vanilla JS. The only annoying part was detecting when the browser was back online, I used some hacky solution since there was no native API for it for any browser at the time, but it worked.